feat: add support for reading OVF data on VMWare

The OVF environment is a way to supply guestinfo to guests. It is
a datastructure (XML) put in `extraConfig` (commonly referred to as
`guestinfo`) under the key `ovfenv`.

This OVF env is said to be the proper way to supply customization data
to guests (ie, not through `extraConfig`), and on some platforms (eg,
vCD), it is even the only option.

This change also enables the actual OVF transport in the OVA.

Signed-off-by: Jorik Jonker <jorik.jonker@eu.equinix.com>
(cherry picked from commit 8b8542e)

cmd/installer/pkg/ova/ova.go

@@ -51,7 +51,7 @@ const ovfTpl = `<?xml version="1.0" encoding="UTF-8"?>
     <OperatingSystemSection ovf:id="101" vmw:osType="otherLinux64Guest">
       <Info>The kind of installed guest operating system</Info>
     </OperatingSystemSection>
-    <VirtualHardwareSection>
+    <VirtualHardwareSection ovf:transport="com.vmware.guestInfo">
       <Info>Virtual hardware requirements</Info>
       <System>
         <vssd:ElementName>Virtual Hardware Family</vssd:ElementName>

go.mod

@@ -81,6 +81,7 @@ require (
 	github.com/talos-systems/talos/pkg/machinery v0.0.0-20210302191918-8ffb55943c71
 	github.com/u-root/u-root v7.0.0+incompatible
 	github.com/vmware-tanzu/sonobuoy v0.20.0
+	github.com/vmware/govmomi v0.24.0
 	github.com/vmware/vmw-guestinfo v0.0.0-20200218095840-687661b8bd8e
 	go.etcd.io/etcd/api/v3 v3.5.0-alpha.0
 	go.etcd.io/etcd/client/v3 v3.5.0-alpha.0